(385a) Revealing Cellulose Pyrolysis Initiation Kinetics Via Novel Milisecond Pulse Reactor System

Biomass pyrolysis is an appealing route for producing fuel and chemicals from renewable resources. Detailed chemical models of pyrolysis chemistry are necessary to optimize the production and composition of bio-oil during pyrolysis. Cellulose, the most abundant biopolymer in lignocellulosic biomass, initially reacts through a short-lived liquid intermediate species which controls the chemistry and determines the composition of bio-oil ^[1]. In this work, a novel millisecond pulse reactor system known as PHASR (Pulse Heated Analysis of Solid Reactions)^[2] is used to study the kinetics of the initiation chemistry of cellulose between 385 ⁰C and 500 ⁰C ^[3]. Using a cellulose surrogate, α-cyclodextrin^[4], the energetics for the initiation chemistry were characterized by measuring conversion from 20 ms to 20 sec. Cellulose decomposition initiation undergoes two distinct kinetic regimes of intra-chain scission; low-temperature glycosidic bond cleavage (T< 467 ⁰C) with a low apparent activation energy and high-temperature glycosidic bond cleavage (T>467⁰C).

References:

1.Dauenhauer, P. J.; Colby, J. L.; Balonek, C. M.; Suszynski, W. J.; Schmidt, L. D., Reactive boiling of cellulose for integrated catalysis through an intermediate liquid. Green Chemistry 2009, 11, (10), 1555-1561.

2.Krumm, C.; Pfaendtner, J.; Dauenhauer, P.J., Millisecond pulsed films unify the mechanisms of cellulose fragmentation. Chemistry of Materials 2016, 28, 3108-3114.

3. Zhu, C.; Krumm, C.; Facas, G. G.; Neurock, M.; Dauenhauer, P.J., Energetics of cellulose glycosidic bond cleavage. Reaction Chemistry and Engineering 2017, 2, 201-214.

4. Mettler, M. S.; Mushrif, S. H.; Paulsen, A. D.; Javadekar, A. D.; Vlachos, D. G.; Dauenhauer, P. J., Revealing pyrolysis chemistry for biofuels production: Conversion of cellulose to furans and small oxygenates. Energy & Environmental Science 2012, 5, (1), 5414-5424.